Levels of Ihsan

Ihsaan comes at many different levels ,the highest of which is one feeling that he is in the presence of Allaah Almighty as the Prophet (alayhi as salaatu wasallam ) explained in the Hadeeth .The level beneath that is seeking closeness to Allaah by performing voluntary deeds; then other acts of Ihsaan follow after that ,regardless of whether those are represented by intention ,objective or action.

أن تعبد الله كأنك تر آه ..)) 
To worship Allaah as if you see Him (Bukharee )

The Prophet's explanation here indicates that the worshipper should worship Allaah in the manner -feeling His closeness ,that He is before Him,and feeling as if he sees Him. What follows necessarily are reverence ,fear ,awe ,and glorification . The wording in the narration of Aboo Hurayrah (radiallahu anhu) is To fear Allaah as if you see Him .

What also necessarily follows is sincerity in worship ,which makes one strive to improve his worship to Allaah ,making it more complete .
Ibn Umar said, When we would make Tawaaf ,we would imagine that Allaah was before our eye."
(Recorded by Aboo Nu'aym in Hilyatul -Awliya 1:309)

And though you do not see Him,He indeed sees you.

This encourages the worshipper to feel Allaah's closeness to him when he is worshipping Him- so that he reaches such a level that it is as if he sees Him. If that is difficult ,the worshipper seeks help through his faith that Allaah is watching him and is aware of not only his outer deeds ,but also of his innermost secrets .The worshipper knows that none of his deeds are hidden from Allaah . When this level is achieved ,it is easy for one to move on to the next level ,and that is to always act as if he sees Allaah and according to the knowledge that Allaah is near and close to him. Know that Ihsaan is made up of two ranks:

1) The rank of sincerity ,and that is for one to worship Allaah ,cognizant of the fact that Allaah sees him and is near to him. When one applies this ,he becomes sincere to Allaah . Remembering that Allaah is near him and knows his deeds when he is actually performing an act of worship prevents one from doing that act for anyone other than Allaah.

2) The rank of Mushahid (observer), and that means for the worshipper to act in conformity to the feeling in his heart that Allaah sees him. This is for the heart to be illuminated with Eemaan and for one to penetrate the depths of knowledge ,until the unseen to him becomes like the seen. And this is the reality of the Ihsaan explained in the Hadeeth of Jibreel .

Important lessons for every Muslim :Shaykh Bin Baz (page 234) English version.

Source,
http://aloloomenglish.net/vb/showthread.php?935-Levels-of-Ihsaan